(1) Field of the Invention
The present invention relates to technology for driving an image display device that uses an organic light emitting diode and in particular to technology for (i) detecting, for an organic light emitting diode or the like whose luminescence properties have deteriorated through extended use, the degree of deterioration of the luminescence properties and (ii) adjusting the luminance.
(2) Description of the Related Art
As a type of image display device that uses a current driven light emitting element, an image display device that uses an organic light emitting diode (OLED), i.e. an organic light emitting display, is well known. Since organic light emitting displays have the advantages of excellent viewing angle characteristics and little power consumption, they are attracting attention as a candidate for the next generation of flat panel displays (FPD).
However, in a display device that uses self-luminous elements such as OLEDs, luminescence properties of the light emitting elements deteriorate through extended use, and thus the display luminance decreases. In particular, in a display device in which such light emitting elements are arrayed, the deterioration of light emitting elements differs according to each element's history of light emission. Therefore, not only does display luminance decrease, but also the display screen becomes uneven (Patent Document 1).
In order to solve this sort of problem, it has been proposed to detect the voltage of an OLED to discern the degree of deterioration, and in accordance with the degree of deterioration of the OLED, adjust the luminance.
Patent Document 1
Japanese Patent Application Publication No. 2003-173869